Grease two, standard 12-cup muffin tins. Set aside.
In a medium bowl, mix together flour, baking powder, baking soda, sea salt and cinnamon, set aside.
In a large bowl, whisk together milk, sour cream, melted butter, maple syrup and eggs.
Add the dry ingredient mixture and stir to combine.
Stir in oats.
Then, fold in blueberries until evenly distributed.
Pour ¼ cup batter into each well of the prepared muffin tins, spacing them out so you will have 7 per tin (this helps them rise better)
Bake 17-19 minutes, ,or until the tops spring back when touched and a cake tester inserted in the center comes out clean.
Let cool in the muffin pans for 20 minutes before removing with a spoon or sharp knife.
Transfer to a wire rack to cool completely.
Video
Notes
Ingredient Substitutions
All-purpose flour. make them gluten-free by using a 1:1 all-purpose gluten-free flour blend. You can substitute up to half of the flour with whole wheat pastry flour.
Whole Milk. Half and half or 2% milk are good substitutes.
Sour cream. full-fat Greek yogurt or plain yogurt work well too. You can also you a vanilla flavored yogurt.
Salted butter. Unsalted butter, coconut oil, canola oil and ghee all work well as substitutes for salted butter.
Old-fashioned oats. quick-cooking oats work well in this recipe too.
Maple syrup. honey is a great substitute.
Blueberries. I suggest fresh blueberries for the best results. If using frozen, be sure to thaw them first in a colander in the sink to drain off any excess liquid.
StoreStore leftover muffins in an airtight container at room temperature for 2 days or in the refrigerator for up to 1 week.FreezeTo freeze, let them muffins cool completely. Then transfer them to an airtight container in the freezer and store for up to 2 months. To thaw, warm in the microwave for 30-60 seconds.